Signal system.



L. A. HAWKINS.

SIGNAL SYSTEM. APPLICATION FILED NOV.29,1907.

1,102,91 6e Patented July 7, 1914.

2 SHEETS-S H EET l.

Fiql.

Wijnzsszslnvenor 7 62m v M Laurence AaWKms,

L. A. HAWKINS.

SIGNAL SYSTEM.

APPLICATION FILED NOV. 29, 1907. 19123 1 6 Patented July 7, 1914.

2 SHEETS-SHEET 2.

Wi fiesses lhv zn or LauvencAHawkins,

UNITED sTArEs PATENT OFFICE.

LAURENCE A. HAWKINS, OF

SCHENECTADY, NEW YORK, ASSIGNGR, BY MESNE ASSIGNMENTS. TO THE UNIONSWITCH AND SIGNAL COMPANY, A CORPORA- TION or PENNSYLVANIA.

SIGNAL SYSTEM.

Patented July 7, 1914. Serial o. 404,211.

To 11/] ?('/I out it 72? my concern Be it known that I, LAURENCE A.HAw-' mm, a citizen of the United States, residing at Schenectady, inthe county of Schenectady, State of New York, have invented certain newand useful Improvements in Signal Systems, of which the following is aspecification.

My invention relates to signal systems for single-track sections ofelectric roads of the type in which counting mechanisms are employed, sothat a plurality of cars passing in the same direction may occupy thesection simultaneously, and the signal at the out-going end will not becleared until the last car has passed from the section.

The object of my invention is to provide a novel system of thischaracter, which shall be reliable in its indications, simple in itsapparatus. and economical in its construction and installation. l

A system of this character should fulfil the following requirements: Thefirst car entering the single-track section should put the signal at theopposite end at danger, and. the operation of the signal at theopposite'end should give an answer back indication. so that the motormancan know positively that the signal at the opposite end has operated. Acaution signal should be given at the end entered by the car, so as toindicate to a following car that the section is occupied by a carpassing" in the same direction. If the second car follows the first oneinto the section, the apparatus should be actuated so that the signal atthe opposite end cannot clear until both cars have left the section.Furthermore, the second car should also receive an answer-back signal toshow that the mechanism at the out-going end has operated to count thatcar. The same operation should be repeat-- ed as each succeeding carenters the section. If a car enters the section and backs out, it mustrestore the signals to their proper con dition. If a car over-runs adanger signal,--that is, enters a section already occupied by a carmoving in the opposite direction, as may occur when the danger signal isthrown in the face of the motorman when he is so close to the signalthat he is unab e to stop before passing it, the signals should be leftin proper condition when the car which is wrongfully in the sectiongle-track section are shown.

backs out. If two cars enter an unoccupied section from opposite endssimultanemisly, neither car should ceive the answer-back or proceedindication. The signals should preferably comprise both lamps for nightservice and semaphores or banners for day service. These devices should.be controlled properly and automatically for the differentcar-movements, above specified, with a minimum number of line-wiresextending through the block. Under no condition should an answer-backclear signal be given, unless the signal .at the other end of the blockis positively at danger.

The system to be described in the following specification fulfils allthe above requirements, and the desired operations are obtained withonly two line-wires, In order to obtain these results, the systemcomprises a number of novel features, which will be specificallypoint-ed out in the appended claims, and which will best be understoodby reference to the accompanying drawings, in which- Figure 1 showsdiagrammatically a signal system for a single-track section of a trolleyroad, arrangedin accordance with my invention; and Fig. 2 shows amodification of the same. I

Signal mechanismsfor both ends of a sinmecha'nisms are similar in everyrespect, and corresponding parts are indicated by correspondingnumerals, the numerals for the left-hand. mechanism being primed. Theright-hand mechanism will be described, and it will be understood thatthis description applies equally to the left-hand mechanism.

1 represents the position of the trolley wire extending through thesingle-track section.

2 and 3 representtwo contacts which are arranged to be connected to thetrolley-wire 1 by the movable contact 4, when a car, respectively,enters and leaves the section from the right-hand end. The arrangen'ientof the contacts 2, and 4, is indicated diagrammatically. In practice anywell known constrimtion of trolley contact may be employed, many ofwhich are well known in the art; It is to be understood that, as usualin such trolley contacts, the device is set the signals nor re- The twoarranged so that the engagement of contact 41 with contacts .2 and 3 isnot merely instantaneous, but is prolonged for a sufficient length oftime to allow the signal mechanism to be actuated. The contact 2 isconnected through a resistance 5 and lamp (3 in parallel to one terminalof the coils 77 of.

a polarized relay 8. 9 represents the polar- 1Z1I10' coil of the relay,which is connected to the trolley-wire through a resistance 10. Thisresistance may be in the form of a lamp so that if the circuit of thepolarized winding'should be broken, notice would be given by theextinguishing of the lamp. As an added precaution, the central.member ofthe relay 8, on which the coil 9 is mounted,

v may be formed from a hard steel permanent wheel arranged to be movedin opposite directions step-by-step by the counting-in magnet 14 and thecounting-out magnet 15. The armature of the magnet 14 is provided with acontact 16, which, when the magnet is energized, short-circuits thegreater portion of resistance 12.

17 represents a switch-arm or contact which is normally supported by apin onthe ratchet 13 in such manner that when the ratchet is moved onestep by the counting-in magnet 141, the arm 17 is allowed to fall fromits front contacts to its back contacts. A. further movement of theratchet 13 in the same direction does not 'move the arm 17,

which remains in the position just described until the ratchet 13 isrestored to its original position, when the pin carried by the ratchetengages the arm in moving through the last step and shifts it from itsback contacts to its front contacts."

18 represents a magnet which is normally connected through the frontcontacts on the armw1'7 to the trolley-wire, and is consequentlynormally energized.

19 represents a semaphore arm which is normally held raised in clearpositiomas shown, but which is dropped to danger position when magnet 18is deenergized.

20 represents a red lamp, which when illuminated serves as the dangersignal at night, and which when the arm 17 is in engagement with itsback contacts is connected through the resistance 21 to trolley.

22 represents a second line-wire, which is connected to/Ure contact 3,and also'to both front and back, contacts on the semaphore arm 19.When'the semaphore arm is in its clear position, line-wire 22 isconnected through lamp 23 and resistance 24: to trol-v ley. Lamp 23,which may be a green lamp, serves as the caution signal. When thesemaphore arm 19 is in danger position linewire 22 is connected tocounting-out magnet 15; the other terminal of which is grounded.

The operation of the system'is as follows: When a car enters the blockfrom the righthandend, a circuit is closed from trolley- 'wire 1,through contacts 1 and 2, resistance 5 and lamp 6 -in parallel, coils 7of polarized relay 8, line-wire 11, coils 7 of relay 8', and resistance12' toground. There is also a branch circuit to ground from the.righthand terminal of coils 7 of relay 8, through resistance 12.Resistances 12 and 12 are 'high compared to the resistances of coils 7and 7', so that the current divides nearly equally between the two pathsto ground. Resistance 5 and resistances 12 and 12 are so proportionedthat the voltage-drop across resistance 5 is not suifieient toilluminate lamp 6. Polarized relays 8 and 8 are so connected thatneither responds to a current flowing through them toward line-wire 11,

while each responds to a current flowing through them from line-wire 11.Consequently, when the circuit, as traced above, is established, relay 8is not afiected, Lam relay 8 shifts its armature into engagement withits contacts. A circuit is then closed from trolley-wire 1 through thecontacts of relay 8 and counting-in magnet 14: to ground. Magnet 1 1 isenergized and shifts ratchetwheel 13 one step in a counter-clockwisedirection, allowing arm 17 to move from its front to its back contacts.This breaks the circuit of magnet 18, allowing semaphore 19 to drop todanger position, and closes the circuit of red lamp 20. The movement ofarm 19' to danger position disconnects lamp 23 from line-wire 22 andestablishes the following circuit: from trol-. .ley-Wire 1 at theright-hand end of the section, through resistance 24, lam 23, frontcontacts of semaphore 19, line-wire 22, back contacts of semaphore 19and count- .ing-out magnet 15 to ground. The resistance of resistance 24and lamp 23 is too great to permit sufficient current to pass togoperate magnet 15, but lamp'23 isilluminated, showing that semaphore 19is at danger position. and at the same time serviing as a caution signalto indicate to fol- .lowing cars that'the block is occupied. A secondanswer-back "indication is given by means of contact 16. When thecounting-in- Zmagnet 14 operates, contact 16 short-circuits the greaterpart of resistance 12, thereby momentarily increasing the currentflowing through line-wire l], ufliciently to illuminate momentarily lamp5. After the lfirstcar has entered the block, if a second givingassurance to the motorman that his car moving in the same directionreaches the right-hand end of the section, it will be warned by lamp :23that there is a car in the section ahead of it, and will consequentlyproceed under control. As it enters the section and brings contact 4into engage ment with contact 2, polarized relay 8 is again actuated andcounting-in magnet 14 shifts ratchet 13 another step. This movement ofthe ratchet does not disturb the position of arm 17', nor does it affectthe signals that have already been set; but it prevents the arm 17 frombeing restored to its normal position, so as to clear the signals untilthe ratchet 13 has been returned two steps. The operation of the magnet14 in shifting the ratchet 13' this second step again short-circuits thegreater portion of resistance 12, so as to again momentarily illuminatelamp 6. Lamp 6 thus acts as an answer-back signal for each succeedingcar,

car has been properly counted in bythe mechanism at the opposite end ofthe block. Vv'hen the first car leaves the section at the left-hand end,a circuit is closed from trolley-wire 1, through contacts 4 am 3,directly to line-wire 22. This connects counting-out magnet 15 directlybetween trolleywire and ground. so that tl1is.magnet operates to returnratchet 13' one step in a clockwise direction. The same thing occurs ifa car that has entered backs out instead of proceeding hrough thesection; the only difference being that the connection from trolley-wire1 to line-wire 22 is formed through contacts +1 and 3, instead of =1 and3. In either case, counting-out magnet 15 is not affected, since itscircuit is open at the back contacts of semaphore 1!), which is at clearposition. If a car over-runs a danger signal, and then backs out, as isnecessary for it to do, the signals will be left in proper condition.For instance, suppose semaphore 11) is at danger; but a car appreachingfrom the left over-runs contact 4; a circuit is then closed from'trolley-vire 1 through contacts 4 and 2 to the upper back contact on arm 17,and through these contacts to line-wire 11. The rigl'it-hand terminal ofcoil 7' is thus connected directly to trolley-Wire, whiletheleft-hand'terminal is connected to trolley-wire through resistance 5.Since coils 7 are of low resistance,

. as has been said heretofore, current will flow through these coilsfromright to left at the same time that current passes through line-wire11, and through coils 7 and resistance 12 to ground,-that is, currentpasses from line-wire 11 through both polarized relays, so that bothpolarized relays are actuated, and both countingin magnets 14 and 14 areconsequently energized, and ratchets 13 and 13' are both shifted onestep. This throws semaphore 19 to danger,

'are connected to line-wire 2.

\ and since semaphore 19 is already at danger, both counting-out magnets15 and 15' Therefore, when the car that has wrongfully entered theleft-hand section backs out again and throws contact 4 into engagementwith. contact 3, both magnets 15 and 15 are actuated, and both ratchetsare returned to the positions they occupied before the car ontered thesection. If two cars enter a clear section simultaneously from oppositeends, both ends of line-wire 11 are connected to trolley-wire and are atthe same potential, so that no currentflows through the line wire, thesignals are not set, and no answerback indication is received by eithercar. Both cars must back out and the first to enter the section againgets control of the signals.

Fig. :2 shows a modification of the system, which is the same in itsessential features the system shown in Fig. 1, but which differs incertain details. In place of the movable contact 4 of Fig, l, thetrolley-wire is shown di-agrammatically as provided with frogs orturn-outs for deflecting the trolley-wheel into engagement with thecontact 2 or 3, according to the direction of movement of the car. Thecontact arrangement of either Fig. 1 or 2, may be used with the circuitconnections of either figure. The spe ifc arrangement of the trolleycontact forms no part of my invention. In F ig. 2, the polarized relaysare omitted and the counting-in magnets 1-1 and 1-1 are placed in serieswith the line-wire 11, and are themselves provided with polarizingcoils. In place of semaphores controlled electrically by the contactarms 17 and 17, light banners 15) and 1!) are employed for the day.signals, and are mechanically connected to the contact arms 17 and 17.The operation of this modification is substantially the same as thatdescribed in Fig. 1. 'A car entering the section at the right closes acircuit from trolley wire 1 through contact 72, resistance 1 5 andanswer-back. lamp (5 in parallel, through the coils of the polarizedcountingin magnet 14,- line-Wire 11, coils of the polarized counting-inmagnet 14, resistance 12 to ground. Resistance 12 forms a branch circuitto ground, as in Fig. 1. The polarizing coils of emu'iting-in magnets14.- and 1+1, instead of being connected permanently to thetrolley-wire, may be connected as shown, since it is not necessarythat-they should be energized, except when the main coils of thecounting-in magnets are energized. Since the magnets 14 and 11 arepolarized, 'magnet 14 alone is actuated, ratchet 13 is shifted one step,brii'igiug contact arm 17 into en a tunent with its back contacts anddropping biirmcr 19 to danger position. The circuit, of the red ordanger lamp 20 1.. slightly different from that shown in Fig. 1. Thiscircuit extends from trolley-wire 1 through resistance 24 and 21' and.lamp to the middle back contact of arm 17, and thence'to ground. Thislamp is thus lighted when the banner 19 is thrown to danger position. iThe circuit of the lamp23, which .acts as a cautionsignal, extends fromtrolley-wire 1 through resistance 24, lamp23,front contacts of arm 17,line-wire.22, lower back.

contactsof. arm ,17', and counting-out magnet 15 to ground. The upperback contacts on arm 17 serve to connect contact'2 to the connectionbetween relay 14 and line-wire,

11, to take care of a car over-running the danger signal in the samewaylas'this event is provided for in the arrangement of Fig. 1'.Additional contacts and 25 are placed on the armatures on counting-outmagnets Y15 and I5. The purpose of these contacts is to maintain closedthe circuitof the'counting-out magnets during the movement of theratchet-wheel over its last step when being returned by the counting-outmagnet to its normal position] This movement of the ratchet through itslast step, by shifting the contact arm from its back contacts, wouldotherwise open the circuit of the counting-out magnet by disconnectingit 30.

- tacts on the armature of the counting-out from line-wire.22. Byproviding the conmagnet, a shunt circuit from line-wire 22 to thecounting-out magnet is closed before or just as the pawl carried by'thearmature engages and shifts the ratchet-wheel. It will beunderstood-that these contacts should be so arranged as to permit afurther movement of the armature of the counting-out magnet after thecontacts have been closed. I have shown in Fig. 2, in connection withthe lamps 20 and 20, an additional feature, which may be applied to theother lamps in the system, as well as to the lamps in the arrangement ofFig. 1. Its purpose is to guard against the burning out of a signallamp,

which is especially-likely to occur in an electric railway signalsystem, since the lamps must be supplied from the power-circuit, the

' voltage of which, in most railways, fluctuof lamp 26 increases, and ifresistance 27 is properly proportioned, the voltage at the terminals oflamp 26 will then be the nor- ,mal voltageoi the lamp. If thevoltage ofi the resistance 27.

the power-circuit is approximately 550, as it is in most direct-currentroads, and it standard llO-volt lamps are used, the voltage drop acrossresistances 2 and 21, when both lamps are burning, should beapproximately 440 'volts,that is, the amount of these re.

sistances should be approximately four times the resistance of theparallelcircuit formed by lamp 20, and lamp 26 and resistance 27. Now,if'resistance 27 is made approximately equal to that of a standard110-volt lamp, then, if lamp 20 burns out, the'voltage across theterminals of lamps 26 will be approximately. 110 volts. It follows fromthis that if standard 110-volt lamps are employed, one of these lampsmay form I have consequently shown two lamps 26 in series, shunting thelamp 20. If all three, lamps are 110-volt lamps, this combination givesthe voltage relations desired.

It will be understood that, I have illustrated "my inventiondiagrammatically, but

any suitable construction may be employed for the several parts of theapparatus.

I do not desire to limit myself to the particular construction andarrangement of parts here shown, but aim in the appended claims to coverall modifications which are within the scope of my invention.

What I claim as new and desire to secure by Letters Patentof the UnitedStates, is

1. In a signal system for-electric railways, a line-wire extendingthrough a single-track section, a polarized magnet connected to.

each. end of said line-wire, a resistance con nected between each magnetand ground, a

contact at each end of the section connected to the connection betweenthe magnet and resistance at that end of the section and arranged to beconnected to the source of power current when a car'enters the sectionatthat end, and signal mechanisms controlled by said magnets.

2. In a signal system for electric railways, a line-wire extendingthrough a single-track section, a polarized magnet connected to each endof said line-wire, a resistance connected between each magnetand-ground, a contact-at each end of the sectioncoiine'cted to theconnection between themagnet and resistance at that end of .the'sec'tionand arranged to be connected to the source of power-current when a carenters the 'sectlon at that end, a step by-step device controlled byeach magnet, and a signal controlled by geach device.

3. In'a signal system for electric railways,

a line-wireextending. through a single-track section, a olarized magnetconnected to .each end 0 said line-wire, aresistance con'--' nectedbetween eachimafg'nctandground, a contact at each "end of thef'se'ctionconnected to the connebtion bet'weenthe magnetfarfd resistance atthatcnd'and arranged'to be connected to the source of poWer-current whena can-enters the section at that end, signal mechanisms controlled bysaid magnets, and means controlled by each signal mechanisni forestablishing a connection from the contact at that end of the section tothe linewire ata point between said magnets.

-i. In a' si nal system for electric railways, a line-wire extendingthrough a single-track section, a polarized magnet connected to each endof said lineswire, a resistance con nectcd between each magnet andground, signal mechanisms controlled by said magnets, and means forsupplying current to the connection between the magnet and theresistance at either end of the section when a car enters the section atthat end.

5. In a signal system for electric railways, a line-wire extendingthrough a, single-track section, a polarized magnet connected to eachend of said coiuluctor, a resistance connected between each magnet andground, signal nurchanisms controlled by said magnets, means forsupplying current to the connection betweenthe magnet and the resistance at either end of the section when a car enters the section at thatend, and means controlled by the signal mechanisms for sup plyingcurrent directly to the line-wire when a signal at one end of thesection is at dangeia'nd a car enters the section at that end. ii. Inasignai system for electric railways, a, line-wire extending through asingle-track section. a signal-controlling magnet and an indicatingdevice connected to each end of said line-wire, means for supplyingcurrent to said line-wire through the magnet and device at one endwhen acar enters the sec tion at that end, said device being non-re- 49sponsive to a current suliicicnt to operate said magnets, and meanscontrolled by the operation of, the magnet at the other end of thesection for increasing the current in the line-wire to cause the deviceat the end of section entered by the car to give its indication.

7. In a signal system for electric railways,

a line-wire extending through a single-track section, asignal-controlling magnet and a 50 returndndication device connected toeach end of said line-wire, means for supplying current to saidline-wire when a car enters the section at one end to actuate the magnetat: the other end, and means controlled by said magnet for controllingthe indication of the device at the end entered by the car.

In a signal system for electric railways,

a line-wire extending through a single-track section, a polarizedsignal-controlling magnet and a return-indication device connected toeach end of said line-wire, a resistance connected between eachmagnet-and ground,

means for supplying current to the connection between the magnet andthefresistance at either end of the section when a car enters thesection at that end, and means c011- trolled by each magnet forshort-circuiting a portion of the resistance connected between it andground.

9. In a signal system for electric railways,

a line-wire extending through a single-track Section, a polarizedsignal-controlling mag" not connected to each end. of said line-wire,aresistance connected between each magnet and ground, a contact at eachend of the section connected to the connection between the magnet andresistance at that end ofthe section and arranged to be connected to thesource of power-current when a car-enters thesectio-n at that end, aretllrn-indication device in series with the contact connection, andmeans controlled by; each magnet for short-circuiting a portion (if theresistance connected between it and ground.

10. In a signal system for electric railways, a line-wire extendingthrough a single track section, a signal controlling magnet and areturu-indication device connected to each end of said line-wire, meansfor supplying current to said line-wire at either end when a car entersthe track section at that end, the magnet at the other end of saidline-wire alone being connected and arranged to respond to said current,and means controlled by said magnet at the other end of said line-wirefor modifying the current in said wire to cause the return-indicationdevice at the end entered by the car to give its indication.

11. In a signal system for single-track sections of electric railways, adanger and a caution signal at each end of the section, means actuatedby a car entering one end of the section for setting the danger signalat the other end, a line-wire extemling through the section to whichwire both caution signals are normally connected, and means controlledby each danger signal for disconnecting the caution signal at that endof the section from'the line-wire, and establishing a connection to saidline-wire for energizing the caution signal at the other 'end.

12. In a signal system for single-track sections of electric railways, adanger signal, a'caution signal, and a controlling magnet at each end ofthe section, aline-wire eX- tending through the section, and meanscontrolled by the danger signal for connecting said caution signal andsaid controlling magnet alternately to said line-wire. I

13. In a signal system for single-tracksections of electric railways, astep-by-step device at each end of the section, a countingin ma net anda counting-out magnet for each device, connectionswhereby the,countingdn magnet-at either end of the section is energized momentarilyupon the entrance of every car at the other end of the section, a dangersignal at each end actuated by the first" movement of the step-by-stepdevice, a caution signal at each end, a linewire extendingv throng-lithesection to which net for each device, connections whereby thecounting-in magnet at either end of the section is energized momentarilyupon the entrance of every car at the other end of.

the section, a danger signal at each end actuated by the first movementof the step-bystep device at that end, a line-wire extending through thesection to which wire both caution si gnalsare normally connected, meanscontrolled by the danger signal'for disconnecting the caution signalfrom that end of the'line-wire and establishing a connection to saidline-Wire through the countingout magnet at that end for energizing thecaution signal at the other end, said magnet being non-responsive to thecurrent energizing. said caution signal, and means connected' to saidline-wire for increasing the current-flow through said magnet when a carleaves the section at either end.

15. In a signal system for single-track sections of electric railways, astep-by-step device at each end of the section, a counting-in magnet anda counting-out magnet -for each device, connections whereby thecounting-in magnet at either end of the section is energized momentarilyupon the entrance of every car at the other end of the section,-a dangersignal at each end ac tuated by the first: movement of the step by stepdevice, a line-wire extending through the section to which wire bothcantion signals are normally connected, both of said caution signalsbeing also normally connected to the source of power-current, meanscontrolled by the danger signal for disconmeeting the caution signalfrom that end of the line-Wire and establishing a connection from saidwire through the counting-out magnet to ground, the caution signal beingof too high a resistance to pennitenough current to pass to operate saidmagnet,'and

means for establishing alow-resistance circuit from the source ofpower-current to said line-wire when a car leaves the section I g ateither end. 1

7 Copies of this patent may he obtained for 1t}. In a signal system forsingle-track sections of electric railways, a danger signal, a cautionsignal, and an answer-back signal at each end of the section, signalcontrolling apparatus at each end of the section including means forsetting the danger signal at one end andthe caution signal at the otherend when a carenters the section at by-step device at that end, acaution signal at each end controlled by the danger signal at the otherend,-and an answer-back slgnal at each end controlled. by each forwardsaid other end, and means controlled by the.

movement of the step-bystep device at the other end.

18. In a signal system for single-track sections of electric roads, astep-by-step device'at each end of the section, means for moving thedevice at either end one step .When a car entersthe other end of the section, a danger signalat each end arranged tobe set'bythe first movementof the stepby-step device at that end, a caution signal at each endcontrolled by the danger signal. at the other end, and an answer-backsignal at each end controlled by each forward movement of thestep-by-step device at the other end, two line-wires extending-throughthe section, and connections whereby the necessary circuit for each ofthe above opertwo Wires and a ground-return.

19. In a signal system sections of electric roads, a s ignalimechanismat each end of the section comprising a step-by-step device, acounting-in magnet, a counting-out magnet, a danger signal, a cautionsignal, and an answer-back signal, two line-wires connecting saidmechanisms, and connections whereby the caution signal and arecontrolled from the other end of the section through one of saidline-wires and the answer-back signal and the other magnet at each endare controlled from the other end of the section through the other wire.

In witness whereof, .I have hereunto set my hand this 27th day ofNovember, 1907.

,IJAURENCE A. HAWKINS.

Witnesses: BENJAMIN B; HULL,

HELEN ORFOBD.

for single-track one of said magnets at each end 7 five cents each, byaddressing the Commissioner of Patents, Washington, 1).. O." 1 1 I00ations is formed by one or the other of said N

